FIDA Diagnostic Diagnostic for FAST IONS : it measures the vertical component of perpendicular energy Processes generating fast ions –Beam –ICRH heating –Nuclear reaction

Beam-Plasma Interaction 2 Collisional ionization beam + plasma e plasma neutrals (halo neutrals) CXRS beam + plasma ions beam ion Re- neutrals CXRS + beam

D  emission from neutrals Neutral population EnergyAtomic ProcessesHH Beam80 KeVElectron collision Doppler shift (60A) + Stark splitting (10A) Edge plasma 10 eVElectron collision unshifted Halo neutrals Plasma energy CXRS (plasma ions-beam) shift Doppler (15 A? for 5keV) Re- neutrals Energetic ions No Mawelliana CXRS ( ions beam- beam) Broad + shift Doppler (max 60 A)

Radiation signal Undesired Signal Signal substruction D  spectral line Beam(Doppler shift canceled by View at 90) Edge plasma Halo neutrals putting a mask in front of CCD Background visible Bremsstrahlung impurity spectral lines Working with a modulated beam D  from Re-neutrals ONLY signal to analyze

LENS COLLECTION f/number: f/4.4 OPTICAL FIBERS 1.5 mm core diameter SPECTROMETER SP-2356 CZERNY- TURNER f/number: f/4 300 mm focal lenght 1800 grooves/mm grating CCD VELOCICAM VC105A rate readout: 2.2 MHz 14 bits chip: 8*6 mm 2 area image chip: 652 vertical columns with 488 pixel Wavelenght range is  = Å Spectral Resolution: 5 Å PROTOTYPE INSTRUMENT 5

CONTAMINANTS IN THE SPECTRUM Lines Impurity OriginElimination B V C VI Excited by charge exchange By beam modulation and time slice subtraction O V C II O IV Noncharge exchange lines By fitting a theoretical response function

Fitting of a theoretical response function The theoretical response function radiated by the impurity is the convolution of: the Gaussian line shape radiated by the impurity the instrumental response (taken by illuminating the fibers with a neon lamp and represented by the sum of three Gaussians)

Spectrum from re-neutrals Born by CXRS fast ions-beam Not Maxwellain distribution function D  spectrum much broader with a non- Gaussian shape

Rotational velocity Measurement vector with parallel and orthogonal direction to magnetic field Doppler shift Ion energy con For view line orthogonal to B

For v z = m/s --> E z = 60 KeV a) b) Any value of Any ion with energy B vzvz Fast ion B vzvz a)b) 

The success of FIDA is based on Vertical views ( Doppler shift only due to gyromotion of fast ions) Blocking bar ( avoiding CCD saturation) Beam modulation ( for substructing background) High quantum efficiency CCD ( for good S/N)

Spectrometers + CCD: characteristics OMAHRSFIDA Focal (mm) F#834.4 grating g/mm (echelle) /D(A/mm) Spectral resolution(A) Slit aperture 20  40  100  CCD pixels1340 x x 488 Pixel size 20  17 x 34  12 